Thermosetting powder coatings have gained considerable popularity in recent years over liquid coatings for a number of reasons. Powder coatings are virtually free of harmful volatile organic compounds (VOC) normally present in liquid coatings, and, as a result, give off little, if any, volatiles to the environment when cured. This eliminates solvent emission problems and dangers to the health of workers employed in the coating operations. Powder coatings also improve working hygiene, since they are in dry solid form with no messy liquids associated with them to adhere to workers' clothes and coating equipment. Furthermore, they are easily swept up in the event of a spill without requiring special cleaning and spill containment supplies. Another advantage is that they are 100% recyclable. Over-sprayed powders are normally recycled during the coating operation and recombined with the original powder feed. This leads to very high coating efficiencies and minimal waste generation.